1. Field of the Invention
The present invention relates to a communications system comprising a message routing method in a system having several different transmission channels.
2. Description of the Related Art
A large number of units which can be either message transmitters or message receivers can be organized in various ways.
One way consists in using several communications channels. Each of these channels is often called a "bus". Each unit of the system desiring to correspond with another unit in this system generally sends a data packet comprising, in addition to the "data to be transmitted" section, "routing" data indicating the paths between different communications channels and possibly the identity of the transmitting unit, and miscellaneous data (error correction codes, acknowledgement of reception, etc . . . ). Such a system functions correctly, but when simple units intended for the general public (sensors, lamps, etc.) are used, it is necessary to add routing storage means to them and to inform them i.e. to enter this routing data, which clearly increases their cost and their complexity.
A transmission protocol for such a system is known from the document "EUREKA 84 Integrated Home Systems Project", ISO/IEC ITC1/SC83WG1 N28 83/WG1 (RYAN 2) of July 1988 or from the Japanese document "Home Bus System" (HB.S)ISO/IEC ITC1/SC83/WG1 N42 of September 1988.